Rouda, a successful businessman who could likely self-fund part of his campaign, raised over $100,000 in independent donations in the 12 days he's been in the race, according to fundraising numbers obtained first by Roll Call. He’s working with fundraising consultant Stephanie Daily Smith, a former fundraiser for Hillary for America.

Rohrabacher ended 2016 with $238,000. His campaign spent about $600,000 during the 2016 cycle, when he won re-election by 17 points.

The 15-term Republican is closely allied with President Donald Trump’s administration, and Democrats hope the congressman’s sympathies toward the Russian government will make him especially vulnerable in 2018. Hillary Clinton won Rohrabacher's 48th District by about 2 points last fall.

Rouda has made investigating election interference from foreign countries one of his campaign promises and has called for an independent prosecutor to oversee those efforts.